Improvement in balanced valves



W. R DUNLAP'. Improvement in Balanced-Valyes. No. 132,526. Patented or. 29,1872'.

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UNITED STATES PATENT OFFICE.

WILLIAM R. DU'NLAP, OF CINCINNATI, OHIO, ASSIGNOR OF ONE-HALF HIS RIGHT TO WARREN WARNER, OFISAME PLACE.

IMPROVEMENT IN BALANCED VALVES.

Specication forming part of Letters Patent No. 132,526, dated October 29, 1872.

To all 'whom it may concern:

Be it known that I, WILLIAM R. DUNLAP, of the city of Cincinnati, in the county of Hamilton and State of Ohio, have invented a certain new and useful Improvement in Valves, of which the following is a specification My improvement consists of a cylinder containing three or more pistons secured to a rod in such relative positions to the ports of the cylinder as to sustain an equilibrium orcounterbalance of pressure at all times and in whatever position or motion the pistons may be.

In the accompanying drawing, Figure l is a central longitudinal section of the valve, the

cylinder of which has a double casing; and Fig. 2 is a View of the valve-gear.

A is the exterior casing, which may be cast in one piece with the branch-pipe a and the annular enlargement b, which terminates in an exit-pipe, c, communicating with a hydrostatic press or other reservoir, H. B is the inner casin g, accurately fitted to the exterior,

except within the annular enlargement or chamber'b, and bored true on the inner surface to secure a water-tight movement of the pistons. e e are orifices, in consecutive diagonal rows, in the inner casing B within the chamber b. Through these orifices the current is conducted into the reservoir H, or discharged thence through the flume d. The pistons C, C1, and O2 are secured on the valve-rod in their proper position by means of pipes g g', inclosing the rod between the pistons, collarsf, and nut h. The relative positions of the pistons are governed by the size and `location of the ports a and exit-pipe c. The distance between pistons G1 and C2 should not be less than the ldistance between the lower part of the chamber b and the upper side ofthe branch-pipe a; and the distance between the pistons C and G1 should be sufficient to inclose between them all the orifices c c.

To illustrate the mode of operating my valve: In the position shown the pistons would permit an uninterrupted flow through the orices e into the reservoir H, and the pressure would equiponderate the two pistons G1 and C2. Assuming the pistons Cl and C2 to be moved to the point indicated by the dotted lines m1 m2, respectively, thus making the piston O to occupy the former place of C1, the iiow will cease, but the equilibrium continues, as there will be an equal counter-pressure upon the adjacent faces of the pistons. In this lposition a discharge from the reservoir H through the fiume d is prevented by the piston C, which permits and regulates this discharge by being moved past the orifices c, and in any position will sustain an equal counter-pressure with the under surface of the piston O1. Thus it will be seen that in whatever position the pistons' are placed within their limits in the cylinder there will be an equal counter-pressure upon any two adjacent faces of such pistons, and, con

sequently, an equilibrium of pressure upon the piston-rods.

What I claim is- 1. Thepistons secured to a piston-rod within a cylinder, substantially as described,where by the pressure through a port therein will counterbalance any two adjacent pistons between which such port is located.

2. The pistons U, G1, and O2, xed to the piston-rod, in combination with the ports a and c, substantially as herein set forth, and for the purpose specified.

3. The pipes g g', in combination with the piston-rod D and pistons G, Gl, and O2, substantially as and for the purpose set forth.

4. The chamber b, in combination with the orifices e and pistons C and O1, substantially as and for the purpose set forth.

5. The-collars f, in combination with the pipes g g', nut h or its equivalent, and pistons C, G1, and G2, for the purpose set forthyand substantially as herein described. WILLIAM R. DUNLAP. Witnesses: p

B. SToEEE, Jr., JOHN E. HATCH. 

